Label-free SERS diagnostics of radiation-induced injury via detecting the biomarker Raman signal in the serum and urine bio-samples based on Au-NPs array substrates.

A sensitive approach based on surface enhanced Raman spectroscopy (SERS) has been developed to evaluate the radiation caused biological injury. To achieve the effective SERS substrate, canonical anodic aluminum oxide (AAO) templates with regular array of nanotips were fabricated, and by plasma sputtering the gold nanoparticles (Au-NPs) were distributed on the nanotips to form the Au-NPs array with plenty of hotspots. The SERS substrates were utilized to examine the serum samples taken from the mice with the treatment of total body irradiation (TBI) of X-ray. The impact of TBI on the mice was analyzed and it was found that the SERS peak intensity at 532 cm-1 increased as a function of duration or dose of TBI. We confirmed that this Raman signature belongs to the myoglobin as a biomarker for the muscle damage due to the radiation caused injury. Furthermore, we also tested several blood and urine specimen of cancer patients who received radiotherapy. The results showed that our approach to some extent could distinguish the bio-samples from normal, X-ray treated and untreated individuals. Therefore, the proposed methodology may have the potential for prompt prognosis of radiation injury at early stage.